Call indicator for automatic telephone systems



J. G. BLESSING. CALL INDICATOR FOR AUTOMATIC TELEPHONE SYSTEMS.

APPLICATION man IULYIO. l9l6. RENEWED IULY 28,1919,-

Patented May 2,1922.

HI Z51" n5 NHED STTES.

PATENT OFFICE.

JOHN G. BLESSING, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

CALL INDICATOR FOR AUTOMATIC TELEPHONE SYSTEMS.

I Specification of Letters Patent.

Patented May 2,1922.

Application filed July v10, 1918, Serial No. 108,324. Renewed July 28, 1919. Serial No. 813,825..

To all whom it may concern:

Be it known that I, Jon G. Bnnssme, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Call Indicators for Automatic Telephone Systems, of which the following is'a specification.

My invention relates to call indicators for automatic telephone systems and has for 1ts object the provision of a com act device of this character which is capab e of registering before an operator a plurality of digits in a called number in response tothe operation of a calling subscribers impulse sender. Such indicators are not altogether new,- having been shown and their functions set forth and explained in a number of issued patents, among which may be mentioned the patent to Clement, No. 1,105,589, and the patent to McBerty, No. 1,117,511. My improved call indicator, however, possesses many new and desirable features not found in previous devices. It comprises, briefly, a plurality of indicating number wheels which I are successively-set y a single operating pawl in accordance with a plurality of series of im ulses. Further invention resides in the mec anical arrangement and design of the various parts whereby a very compact construction is-obtained.

These features together with others not specifically mentioned will' appear more clearly and will be more readily understood from an inspection of the detailed specification and the accompanying drawings,

In the drawings, Fig. 1 represents an end view of my improvedcall indicator, Figs. 2 and 4 are top and bottom views, respectively, while Fig. 3 is a side view with one of the frame plates removed and theend piece cut away to more clearly show the mechanism. Fig. 5 .is a circuit'diagram showing the wiring connections of the device by which it may be controlled from a subscribers telephone. Fig. 6 is a detailed showing of one of the number wheels. Referring now to Figs. 1, 2, 3, 4, and 6,

the various parts are mounted in a frame which comprises two brass side plates 2 and 3 which are separated the proper distance and rigidly connected by the end piece 4 and the top mounting plate 5. The frame is given additional strength and, rigidity by the cores of the magnets 6,7, and 8 which are secured at opposite ends to the frame plates 2 and 3 by countersunk screws (not shown). clearly shown in Fig. 1, enables the operator to perceive the number which has been registered by the setting ofthe number wheels.

In Fig. 1 the various number wheels are assumed to have been set in accordance with the digits which appear. When all the wheels are at rest no numbers are to be seen for the space just. to the right of tooth 13 (Fig. 6)-is a blank.

Ad acent to the endpiece 4, the shaft 6, passing through the plate 3 and secured at the other end to plate 2. by the screw 9, affords a means for mounting the number wheels and the releasev control wheel 10. Each nu'mber Wheel and also the release control Wheel is provided with aminiature clockspring such as the spring 100 shown in Fig. 6 by means of which they are normally held in the position shown in Fig. 2. Each clock spring is carried on the inside vof its associated wheel and is fastened at one end to the wheel and at the other end to the An opening in the end piece 4:,

shaft 6, as may be seen clearly by reference 7 to Fig. 6. The normal position of the number wheels is determined by the ratchet tooth 13 of each wheel which, being somewhat higher than the rest, engages the lower edge screw 9 is first loosened and the'shaft 6 is then rotated in a counter clock-wise direction (see Fig. 6) whereby all the springs are tightened, after which the shaft 6 is locked by means of the screw9.

The operating pawl 15 1s rotatably and 'slida-bly mounted upon a reciprocating car-' riage which comprises a cross bar 18 and a rod 17 secured together at one end by "the piece 20 and at the other end by the The carriage triangular shaped piece 21. is pivoted on a. rod 19 which passes through frame plates 2 and 3 and through bearings in pieces 20 and 21. A; small rod 42 extends from end piece 20 to end piece 21 parallel to rod 17 and a short distance below it. The downwardly extending end of spring 43 is slipped behind this rod, the

-' number wheels when it is moved forward.

. the control of magnet 7. The pole pieces 27 rocating carriage.

While the lower end of spring 43 is con-.

cealed from view in Fig. 2, the method of tensioning this spring is similar tothe method employed in tensioning spring 36, which is clearly shown in Fig. 4. The movement of the reciprocating carriage is controlled by the armature 14 of the magnet 6 through the. medium of arm 23 which engages a roller 22 mounted on'the lower corner of thetriangular piece 21. The armature 14 is pivoted on a rod W1 passing through the frame plates as shown. It will now be easily understood that when the armature 14 is attracted by pole pieces 25 and 26 of magnet 6 the u per end ofarm 23"- (F ig. 3) will be move to the left, thereby'rotating the carriage in a clockwise direction about the rod 19 as an axis and bringing the pawl 15 into engagement with the notch on wheel 10.

For retaining the number wheels in set position and also to prevent backward rota tion during setting, there is provided a comb32 of spring brass' which is attached by'screws to the plate 31. Theplate 31 is provided at each end with an upturned portion, one of which is'indicated by reference character 35, by means of which the plate 31 is pivoted on the rod 19 just inside the end pieces 20 and 21 of the recip- A tailpiece 34 is engaged by the spiral spring 36 whereby the plate 31 is normally held with the arm 33 resting against -the roller 12- carried on wheel 10. By referring now more particularly to Fig. 3 it will be seen that'when the release control wheel 10 is rotated by.

the pawl 15 the roller 12 will engage the arm 33 and will rotate the=plate 31 ina counter clock-wise direction about the rod 19 as an axis, whereby the teethof the comb 32 are brought into positionflto engage the teeth of the number wheels.

The release control wheel 10, when rotated is locked by the spring dog 37 under and 28 of magnet 7 are bent inwardly and lie upon the top of plate 5. The armature 40 iszpivoted. on the larger portion of the offset pivot screw 39 which i screwed into the top mounting plate 5. en the magnet 7 is energized the armature 40 is rotated in a clock-wise direction, thereby withdrawing the rod 38 from engagement with thespring dog 37 which latter is thus allowed to engage the detent in the. wheel 10 when the same is rotated.

It has been mentioned before that the pawl 15 is slidably mounted on the rod 17 of the reciprocating carriage. In Fig. 2 the pawl 15 is shown in its normal position. It is movable from right to left in successive stages under the control of the armarotatably and slidably pivoted on the rod 45. A roller 46. carried by armature 44 engages a curved cam like projection on' the frame plate 2 when the armature is attracted there-bymovingvthe armature endwise from left to right (Fig. 2) at the same time it is moved around its pivot. The lever 41' is pivoted on the pivot screw 39 independent of armature 40 and carries at one end a pin 48 which fits in a slot in the pawl 15. It will be readily apparent from the foregoing that when the armature 44 is attracted the cam 51 will engage the first tooth in the rearend of lever 41 whereby the lever 41 will be rotated about pivot 39 to shift the pawl 15 into position adjacent the first number wheel. The lever 41' is held in its successive positions by the dog 49. Arm; 50 carried on the "armature 40 normally holds the dog 49 out of engagement with the inner teeth of pawl 15 will 'now be given, which could not be conveniently explained before. The front stop for this pawl comprises a rearwardly extending portion 53 of the end piece 4 and is provided to prevent the pawl 15 from disengaging the notches in the number wheels (Figs. 2 and 3). The back stop, by which the pawl when retracted is raised from engagement with the number wheels, comprises a crossbar 16 rigidly attached to the plate 31. It will be seen from Fig. 3 that the pawl 15 is provided with a downwardly extending tail iece 52 which engages the cross bar 16. ow whenever the plate 31 is shifted by the release control wheel 10 the cross bar- 16 attached to the said, plate will allow the pawl to rotate slightly under the tension of spring 43 so that the end of the pawl will be able to engage the teeth of the number wheels when the pawl is thrust forward. The notch on the release control wheel 10 which the pawl engages is set fordogs, etc. are provided with suitable springs by which they arereturned to normal position at the proper time. Referring to Figure 2, the spring.'102 is for restoring the armature 40 to normal, the spring'103 is for restoring the lever 41 to normal position, and the spring 101 is for pressing thejdog 49 1nto engagement with the inner teethfin the lower on of the lever 41 when the arma ture 40 is attracted, while the spring 104 1,414.,eae

(Fig. 4)" is for restoring the armature v to normal position and may be similar to the spring 36.

The contact springs by which the circuits of magnets 7 and 8 are controlled are.

with a bushing 60 by means of which the three springs corresponding to armature 72 and contacts 73 and 74 of Fig. 5 are controlled. The armature 40 of magnet 7 is likewise provided with a bushing 61' by means of which springs corresponding to 'armature. 74 and contact 75 of Fig. 5 are controlled. -While the arrangement of contact springs and terminals shown herein is very compact and convenient, this precise construction need not be adhered to so long as the proper circuits are retained.

Having explained the mechanical construction of my improved call indicator I will now describe briefly its operation in registering a call. The magnets of thecall indicator respond to impulses received in the same manner as do the principal controlling relays of a connector switch in an automatic telephone system of the type with which the 1 indicator is adapted to be used. Such a system is shown in'the patent to New'forth, No. 13,901, reissued April 13, 1915, and it may be stated that the magnets 6, 7, and 8 of myimproved call indicator correspond,

insofar as their operation is concerned to the line, release, and control relays shown in the, connector switch of that patent. To proceed and referring to Fig. 5 of the drawings when the subscriber at the automatic substation A- removes his receiver prelim inary to making a call, his line is extended in well known manner through the medium of an individual line switch C to a selector switch E. The calling subscriber may now manipulate his calling device D, which may be of the type shown in the British patent to Dicker No. 29,654 of 1910, in accordance with the first digit of the desired number. A series of interru tions of the line circuit is thus produced whereby the selector E is operated to extend the line conductors to the operators cord circuit P, of which only a1 .fragmentar portion isshown. The controlling relay 0, in bridge of the two strands of the-cord and in series with a battery, is then energized over the calling subscribers loop.

Upon attracting its armature, the relay completes a circuit from ground by way of conductor 71 to the magnet 6 of the call indicator. Magnet 6, upon energizing, at-

tracts the armature 14 with the following results: The reciprocating carria e is operated to rotate the release contro wheel 10 through the medium of pawl 15; and a circuit is completed .for the magnet 7 which extends from ground by way of armature 72, contact 73 and winding of the said magnet 7 to the ungrounded pole of battery. Magnet 7, upon energizing, rotates its armature 40, thereby withdrawing the rod 38 from engagement with the spring dog 37 40 the arm 50 is moved to the left to free" the dog 49. As a still further result a circuit is prepared for magnet 8 by the engagement of armature 74' with contact 75.

The calling subscriber may now operate his calling device in accordance with the second digit of the desired number thereby producing a series of interruptions in the circuit of relay 70. By the alternate retraction and attraction of its armature, relay 70 produces a corresponding series of' interruptions in the circuit of magnet 6. At each retraction of its armature magnet 6 closes a circuit for magnet 8 as follows: Grounded armature 72, contact 74, armature 74, contact 75, and the winding of magnet 8 to the ungrounded pole of battery. Magnets 7 and 8 are each provided with a heavy slug of copper to make them slow acting so that they retain their armatures during vibrations of the. armature of magnet 6. When the magnet 8 is energized at the first retraction of the armature of magnet 6, the armature 44 controls the lever 41 to shift the pawl 15 into position before the first number wheel. It will be plain now that the intermittent attractions of armature 14 which follow immediately after its first retraction result in the setting of the first number wheel 'in' accordance with the second digit of the number called since the first series of impulses operated the selector E to extend the line conductors to the cord circuit At the end of the series of interruptions the magnet 8 is deenergized, the lever 41 being retained in position by the dog 49.

As the calling subscriber calls the remaining digits of the wanted number the apparatus responds as before for each digit; it being understood that at the first deenergization of magnet 6 in each series, the magnet 8 shifts the pawl 15 into position before apparatus suitable for this purpose is well known and since my invention is not limited to use in connection with any particular type of apparatus it is not thought to be necessary or advisable to show these circuits in detail.

When the calling subscriber replaces his receiver the call register is restored to normal position by the deenergization of relay 70 and the consequent deenergization of magnet 6. The armature of magnet 6 upon restoring, breaks the circuit of magnet 7 which latter, upon deenergizing, forces-the dog 37 out of engagement with the release control wheel 10 through the medium of rod 38. When the release control wheel returns to normal, the plate 31 carrying the comb 32 restores, whereby the number wheels are released. As a'further result of the deener ization of magnet 7, the arm 50 knocks the 0g 49 out of engagement with the teeth of lever 41, whereby the pawl 15 is returned to its normal position. I

It will be seen from the foregoing that I have devised an exceedingly compact and convenient call indicator of the character de,

scribed. While the device is shown in its preferred form, it is probable that modifications, particularly in the controlling circuits, may be' made without departing from the spirit-of the invention. I desire, therefore, to include and have protected by Letters Patent all forms and modifications of my invention which may come within the scope of the appended claims.

What I claim as my invention iSi -1. In an indicating device a plurality of number wheels rotatably mounted on a shaft, a 'reciprocating carriage disposed parallel to sald'shaft, an operating pawl slidably mounted thereon, and means for shifting said pawl sidewise along said carriage into successive positions corresponding each to a different number wheel.

' 2. In an indicating device a plurality of numberv wheels 'rotatably mounted on a shaft, a reciprocating carriage disposed parallel to said shaft, an operating pawl slidabl mounted thereon, means .for shifting sai pawl sidewise along said carriage into successive positions correspinding each to a difi'erent number wheel, and means for operating the carriage when the pawl is in each posltion to set the corresponding num ber wheel. i

3. In a i call indicator the combination with a plurality of number wheels and an operating pawl therefor,,of a carriage-com:

tion with a pluralit of in icators and a magnet, of means w ereby said magnet is said paw repeatedly into engage-t 4. In an indicating devicel thecombinaprising a-slide for, said pawl, means for enabledto set. said indicators separately, 7

said means comprisin a reciprocatin carriage controlled by t e armature o 7 said magnet, an operating member mounted thereon, and means for moving said meme ber to a plurality of positions on said carria e, said member bein adapted to set a di 'erent indicator in eac position.

5. In a call indicator, the combination with a plurality of number wheels, of a common operating member for said wheels, detents for retaining said wheels in operated position and normally out of operative;

relation therewith, meansfor operating said member'to set said wheels, and means controlled in the first movement of said member to bring said detents into operative relation with-said wheels.

6. In a call indicator, a plurality of number wheels, retaining pawls normally out of engagement with said wheels, a common opcrating pawl, a circuit contaminga magnet for actuating said pawl, means controlled by said pawl upon the first closure of said circuit for bringing "said retaining pawls into engagement with said wheels, and means controlled by said magnet upon the first succeeding interruption of said circuit for shifting said pawl into association with the first of said number wheels.

7. In an indicating device for recording calls in a telephone system, a set of indicator' wheels, means for advancing said wheels one at a time, and means comprising mechanism operated by a slow acting magnet and a pawl mechanism for holding thewheelsin their advanced position.

8. In an indicating device for recording calls in a telephone system,Ia set of indie;- tor wheels, means for advancing said wheels one at a time, and means comprising mechanism operated by a slow acting magnet and a pawl mechanism for holdin in their advanced position, sai first means comprising a nick acting magnet.

9. In an in icating device for recording calls in a telephone system, a set of indica tor wheels means for advancing said wheels one at a time, and means comprising mechamsm operated by a slow acting magnet and the wheels a pawl mechanism for holdin the wheels 7 in their advanced position, sai first means comprisin a quick acting magnet, the circut of sai slow acting magnet controlled by said quick acting magnet.

10. In an indicating device for recording calls in a telephone system, a set of indi-' in their advanced position, and a slow acting magnet for controlling said mechanism mal, said first to remove the mechanism from said wheels to lpermit the wheels to be restored to norma 11. In an indicating device for recording calls in a telephone system, a set of indicator wheels, means for advancing said wheels, a pawl mechanism for holding them in their advanced position, and a slow acting magnet for controlling said mechanism to remove the mechanism from said wheels to permit the wheels to be restored to normeans comprising a quick acting magnet, the circuit of said slow acting magnet controlled by the quick acting magnet.

12. In an indicating device for recording calls in a telephone system, a set of indicator wheels, means for advancing said wheels one at a time, said means comprising mechanism operated by a slow acting magnet, and a pawl mechanism for holding said wheels in advanced position together with a second slow acting magnet for removing said awl mechanism from said wheels to permit their restoration to normal position.

13. In an indicating device for recording calls in a, telephone system, a set of indicator wheels, means for advancing said wheels one at a time, said means comprising mechanism operated by a slow acting magnet, and a pawl mechanism for holding said wheels in advanced position together with a second slow acting magnet for removing said pawl mechanism from said wheels to permit their restoration to normal position, said first means comprising a quick acting magnet, the circuits of both of said slowacting magnets controlled by said quick acting magnet.

14:- In an indicating" device for recording calls in a telephone, system, a set of indicator wheels, means for advancing said wheels one at a time, said means comprising mechanism operated by a slow acting.

magnet and a pawl mechanism for holding sai w eels in advanced position together with a' second slow acting magnet for removing said pawl mechanism from said wheels to permit their restoration to normal position, said first means comprising a quick acting magnet, the circuits of both of said slow acting magnets controlled by said quickacting magnet, the circuit of one of said slow acting magnets being closed when the quick acting magnet is deenergized and the circuit of the other slow acting magnet being closed when the quick acting magnet is energized.

15. In a telephone system, an indicating device havin a number wheel corresponding to each igit of a called number, a retaining pawl for said wheels, a driving pawl, a magnet for operating said driving pawl to first cause said retaining pawl to engage all of said wheels and for then operating said drivingpawlto rotate said wheels successively to set up on said wheels a called subscribers number.

16. In a telephone system, an indicating device, havinga number wheel corresponding to each digit of a'called number, a re taming pawl for said wheels, a driving pawl, a magnet for operating said driving pawl to first cause said retaining pawl to engage all of said wheels and for then operating said driving pawl to rotate said wheels successively to set up on said wheels a called subscribers number and means for then operating said retaining pawl to release said wheels.

17. In a telephone system, an indicating device havin a number wheel corresponding to each igit of a called number, a retaming pawl for said wheels, a driving pawl, a magnet responsive to successive series of impulses to first cause said retaining pawl to engage said wheels and for then operating said wheels successively to set up the called subscribers number, means operated by saidmagnet between successive series of impulses for shifting said driving pawl from one wheel to the next, and means controlled by said magnet for thereafter re-' JOHN G. BLESSING. 

